الفهرس 
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Abstract
Ovarian cancer is one of the most common causes of cancer related-deaths in females. It is the 8th most common cancer among women in the world and is considered the 5th cause of cancer related death in women with a higher mortality rate than all cancers of female genital tract.
Ovarian cancer is the leading cause of death in women diagnosed with gynecological cancers. Most of the cases are diagnosed at an advanced stage, which leads to poor outcomes of this disease. The screening tests have a low predictive value, Gynecological evaluation along with transvaginal ultrasound and laboratory marker like cancer antigen-125 (CA-125) assay are the key early detection strategies which have shown no significant beneficial effect in the morbidity or mortality of this cancer.
There are different subtypes of ovarian cancer. Based on the morphology of tumor cells, the ovarian cancer was divided by histological subtype as serous, endometrioid (EC endometrioid carcinoma), mucinous (MC mucinous carcinoma), with clear cells and squamous cells (CCC for clear cell carcinoma and SCC for squamous cell carcinoma).
It is necessary for screening of ovarian cancer the presence of biomarkers in conjunction with imaging explorations in order to increase the chances of detection of ovarian cancer in the early stages. Today, ovarian cancer is detected in advanced stages (stage III or IV) at the earliest stage II, based on transvaginal ultrasonography and increasing levels of CA 125 because of the absence of symptomatology.
Among the biomarkers that are considered to have potential in the early detection and monitoring of different types of cancer, there are the small, highly conserved non-coding RNA molecules called microRNAs (miRNAs).
miRNAs are a class of single-stranded, short segments of RNA (of ” ” ” " ~ " ” ” ”22 nt) that can suppress gene expression by binding to complementary segments of messenger RNA and interfere with the formation of proteins by translation.
miRNAs interact with the 3’untranslated region (3 UTR) of mRNA, but their interaction with other regions was also reported, such as the 5 UTR, coding sequence, and gene promoters. miRNA post-transcriptionally regulates gene expression, including that of genes involved in the development and progression of cancer.
Dysregulated miRNAs may change the pattern of gene response and could be associated with oncogenic activities as cell proliferation, apoptosis, invasion, angiogenesis, stem cell maintenance, tumor growth, cell response. These small molecules regulate about one-third of genes in the human body and can modulate countless messenger RNAs (mRNAs), permitting the regulation of gene expression.
miRNA-613 is a newly-discovered miRNA and the exact role of miRNA- 613 was firstly reported in 2011 that directly target liver X receptor (LXR) gene and ensure a tight regulation of LXR in many metabolic functions.
miRNA-613 was downregulated and serve as a potential cancer suppressor in various kinds of cancer including ovarian cancer, esophageal squamous cell carcinoma, colorectal cancer, non-small cell lung cancer, osteosarcoma.
miRNA-613 was downregulated in ovarian paraffin blocks compared to control group this mean that miRNA-613 was down regulated in ovarian cancer.
KRAS is a member of the RAS superfamily RAS-like GTPases. It is important in the RAS/ MAPK pathway and regulates several signal transduction pathways. KRAS is a molecule involved in ovarian cancer progression and development.
KRAS expression was higher in ovarian cancer tissue compared with normal human ovarian tissue. KRAS reverse the effects of miRNA-613 on ovarian cancer cell proliferation and invasion. We demonstrate that miRNA-613 regulates KRAS expression and thus functions as a tumor suppressor gene in ovarian cancer.
Ezrin is an important signaling molecule that is well-documented to be associated with many cellular processes, including cell proliferation, cell adhesion, cell motility, signal transduction. Ezrin, a member of the ezrin–radixin–moesin(ERM) family, is not only a key membrane cytoskeletal cross linker, but also involved in signal transduction.
Ezrin controls signaling transduction by interacting with adhesion molecules and various growth factor receptors. Ezrin’s has roles in tumor growth, metastasis, and morphogenesis in cancer biology, because increased Ezrin expression is correlated with poor prognoses in various cancers.
Our results show a highly increase in the expression of Ezrin gene in ovarian cancer tissue indicating that Ezrin gene expression is upregulated in ovarian cancer. Ezrin expression is increased in metastatic ovarian cancer. The highest levels of Ezrin were observed in the metastatic tissue.